I like the idea of your paper bags quite a bit; shows innovation and an understanding of using toned mediums for life drawing.
Also like your Bridgmans. Pay very close attention to those... meaning... stare at and study them before copying. Look at the relationships. Try to re-interpret what you see.
Proportions, proportions, proportions. Nail those, and 80% of your work is done. Make them unconscious. But to do that, you need to be conscious of them first. Measure. Use a ruler if you have to at first. Training wheels.
Hope you have great fun and luck this week